I've added 2 external USBs of 2TB each to my Proxmox server and created a Resource Pool called USB_HDD containing both.
I created an Ubuntu VM, but I can't allocate all 4TB to it in one go - it only allows me to add each one as a separate SCSI device. When I start to install the OS it only allows the install onto one of the 2TB devices.
I though the point of pools was to make the actual disks transparent, and present the pool to the VM so it sees it as one lot of space.
Am I doing something wrong, or do I have to have it as 2x2TB disks?
As per the documentation, pools are basically just resource groups to make permission management easier, so they aren't really supposed to handle anything like that. Maybe look into a RAID setup of some sort or mergerfs if you just need file level pooling.